Ontogenetic variation in the crocodylian vestibular system DOI
Julia A. Schwab, Mark T. Young, Stig Walsh

et al.

Journal of Anatomy, Journal Year: 2021, Volume and Issue: 240(5), P. 821 - 832

Published: Nov. 28, 2021

Abstract Crocodylians today live in tropical to subtropical environments, occupying mostly shallow waters. Their body size changes drastically during ontogeny, as do their skull dimensions and bite forces, which are associated with prey preferences. Endocranial neurosensory structures have also shown change ontogenetically, but less is known about the vestibular system of inner ear. Here we use 30 high‐resolution computed tomography (CT) scans three‐dimensional geometric morphometrics investigate shape crocodylian endosseous labyrinths throughout across four stages (hatchling, juvenile, subadult adult). We find two major patterns ontogenetic change. First, labyrinth increases negative allometry relation size. Second, significantly, hatchlings having shorter semicircular canal radii, thicker diameters an overall dorsoventrally than those more mature individuals. argue that modification ontogeny related constraints imposed by growth, due fundamental braincase (e.g. verticalisation basicranium), rather locomotion, diet, or other biological functions behaviours.

Language: Английский

The history, systematics, and nomenclature of Thalattosuchia (Archosauria: Crocodylomorpha) DOI Creative Commons
Mark T. Young, Eric W. Wilberg, Michela M. Johnson

et al.

Zoological Journal of the Linnean Society, Journal Year: 2024, Volume and Issue: 200(2), P. 547 - 617

Published: Jan. 9, 2024

Abstract The use of more than one nomenclatural code is becoming increasingly common in some biological sub-disciplines. To minimize instability, we have decided to establish a higher level systematization for Thalattosuchia under both the International Code Phylogenetic Nomenclature (‘PhyloCode’) and Zoological (‘Zoological Code’). We undertook series phylogenetic analyses with an expanded dataset examine origins within Crocodylomorpha, determined clade’s diagnostic characters. Based on these analyses, provide updated diagnoses its subclades PhyloCode Code. also introduce two new nomina that are regulated (Neothalattosuchia Euthalattosuchia), nomen Dakosaurina, which registered codes. Moreover, PhyloCode-compliant definitions subclades. As cannot reliably discriminate between positional hypotheses clades’ as much mystery today they were over century ago. However, hope using same characters define clades, nomina, codes will be example others follow.

Language: Английский

Citations

14
Deep evolutionary diversification of semicircular canals in archosaurs DOI Creative Commons
Mario Bronzati, Roger Benson, Serjoscha Evers

et al.

Current Biology, Journal Year: 2021, Volume and Issue: 31(12), P. 2520 - 2529.e6

Published: April 29, 2021

Language: Английский

Citations

49
Digital skull anatomy of the Oligocene North American tortoise Stylemys nebrascensis with taxonomic comments on the species and comparisons with extant testudinids of the Gopherus–Manouria clade DOI Creative Commons
Serjoscha Evers,

Zahra Al Iawati

Swiss Journal of Palaeontology, Journal Year: 2024, Volume and Issue: 143(1)

Published: March 5, 2024

The anatomy of North American tortoises is poorly understood, despite a rich fossil record from the Eocene and younger strata. Stylemys nebrascensis particularly noteworthy turtle in this regard, as hundreds specimens are known Oligocene deposits, species one earliest turtles to have been described scientific literature. Since its initial description based on shell, many with more complete material referred nebrascensis. Here, we review confirm referral an important historic specimen nebrascensis, which includes non-shell postcranial, skull material. This allows us document unique features (e.g., unusual 'poststapedial canal' that connects posterior surface cavum acustico-jugulare) refer another well-preserved species. Based computed-tomography scanning these two skulls, provide detailed cranial mandibular osteology has combination plesiomorphic characteristics retention medial jugal process) derived traits shared extant gopher median premaxillary ridge) suggest it may be stem-representative tortoise lineage. supports hypothesis America form geographically restricted clade split Asian relatives during Paleogene.

Language: Английский

Citations

6
Evolution of sensory systems DOI

Pablo Oteíza,

Maude W. Baldwin

Current Opinion in Neurobiology, Journal Year: 2021, Volume and Issue: 71, P. 52 - 59

Published: Sept. 29, 2021

Language: Английский

Citations

36
Independent origin of large labyrinth size in turtles DOI Creative Commons
Serjoscha Evers, Walter G. Joyce, Jonah N. Choiniere

et al.

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Oct. 11, 2022

Abstract The labyrinth of the vertebrate inner ear is a sensory system that governs perception head rotations. Central hypotheses predict shape and size are related to ecological adaptations, but this under debate has rarely been tested outside mammals. We analyze evolution morphology its drivers in living fossil turtles, an understudied group underwent multiple locomotory transitions during 230 million years evolution. show turtles have unexpectedly large labyrinths evolved origin aquatic habits. Turtle relatively larger than those mammals, comparable many birds, undermining hypothesis correlates directly with agility across vertebrates. also find variation does not correlate ecology widespread expectation reptilian shapes convey behavioral signal, demonstrating importance groups, like turtles.

Language: Английский

Citations

27
Anatomy and relationships of the early diverging Crocodylomorphs Junggarsuchus sloani and Dibothrosuchus elaphros DOI
Alexander Ruebenstahl,

Michael D. Klein,

Hongyu Yi

et al.

The Anatomical Record, Journal Year: 2022, Volume and Issue: 305(10), P. 2463 - 2556

Published: June 14, 2022

Abstract The holotype of Junggarsuchus sloani , from the Shishugou Formation (early Late Jurassic) Xinjiang, China, consists a nearly complete skull and anterior half an articulated skeleton, including pectoral girdles, forelimbs, vertebral column, ribs. Here, we describe its anatomy compare it to other early diverging crocodylomorphs, based in part on CT scans that Dibothrosuchus elaphros Early Jurassic China. shares many features with cursorial assemblage informally known as “sphenosuchians,” whose relationships are poorly understood. However, also displays several derived crocodyliform not found among most “sphenosuchians.” Our phylogenetic analysis corroborates hypothesis is closer Crocodyliformes, living crocodylians, than Sphenosuchus but close crocodyliforms Almadasuchus Macelognathus “Sphenosuchia” paraphyletic assemblage. D. acutus hypothesized be more closely related Crocodyliformes remaining non‐crocodyliform which form smaller groups largely unresolved.

Language: Английский

Citations

24
Cranial osteology and paleoneurology of Tarjadia ruthae: An erpetosuchid pseudosuchian from the Triassic Chañares Formation (late Ladinian‐?early Carnian) of Argentina DOI
Julia B. Desojo, M. Belén von Baczko, Martín D. Ezcurra

et al.

The Anatomical Record, Journal Year: 2024, Volume and Issue: 307(4), P. 890 - 924

Published: Jan. 23, 2024

Abstract Tarjadia ruthae is a quadrupedal terrestrial pseudosuchian from the Middle‐early Upper Triassic of Chañares Formation, La Rioja Province, Argentina. Originally, this species was identified as an indeterminate archosaur and later doswelliid archosauriform based on very fragmentary specimens characterized by ornamentation skull roof osteoderms. Additional (including skulls postcrania) recovered in last decade show that erpetosuchid, enigmatic group composed six registered Middle‐Upper continental units Tanzania, Germany, Scotland, North America, Brazil, Argentina Parringtonia gracilis Tanzania are best preserved more abundant species. Although monophyly Erpetosuchidae well supported, alternative high‐level positions within Archosauria have been suggested, such sister taxon to Crocodylomorpha, Aetosauria, or Ornithosuchidae. In order improve knowledge about erpetosuchids, we performed detailed description paleoneurological reconstruction , two articulated partial (CRILAR‐Pv 478 CRILAR‐Pv 495) other specimens. We analyzed stratigraphic geographic occurrence historical new provided emended diagnosis (the same for genus species, due monotypy) along with comparative cranial endocast. The robust, thick strongly ornamented roof, triangular dorsal view, concave lateral margins at mid‐length form abrupt widened posterior region. external nares smallest openings skull. antorbital fossa deeply excavated has small heart‐shaped fenestra both lobes pointing anteriorly. supratemporal fenestrae large rounded orbits, infratemporal L‐shaped extensive excavation jugal, quadratojugal quadrate. hemimandibles low, slightly dentigerous region convex region, conferring them S‐shaped profile view. mandibular elliptic, being twice longer than high. maxillary dentition restricted anterior mid rostrum. Since braincase partially damaged, surface brain could not be entirely reconstructed. As result, endocast anteroposteriorly elongated seemingly flat, cephalic flexure seems lower expected suchian. labyrinth wider high, semicircular canals remarkably straight, canal one.

Language: Английский

Citations

5
Endocranial anatomy and phylogenetic position of the crocodylian Eosuchus lerichei from the late Paleocene of northwestern Europe and potential adaptations for transoceanic dispersal in gavialoids DOI Creative Commons
Paul M. J. Burke, Sophie A. Boerman, Gwendal Perrichon

et al.

The Anatomical Record, Journal Year: 2024, Volume and Issue: 308(2), P. 636 - 670

Published: Sept. 3, 2024

Abstract Eosuchus lerichei is a gavialoid crocodylian from late Paleocene marine deposits of northwestern Europe, known skull and lower jaws, as well postcrania. Its sister taxon relationship with the approximately contemporaneous species minor east coast USA has been explained through transoceanic dispersal, indicating capability for salt excretion that absent in extant gavialoids. However, there currently no anatomical evidence to support adaptation extinct Furthermore, placement within Gavialoidea labile, some analyses supporting affinities Late Cretaceous early Paleogene “thoracosaurs.” Here we present novel data on internal external anatomy E. enables revised diagnosis, 6 autapormorphies identified genus 10 features enable differentiation . Our phylogenetic recover an diverging gavialid not part “thoracosaur” group. In addition thickened semi‐circular canal walls endosseous labyrinth paratympanic sinus reduction, identify potential osteological correlates glands surface prefrontal lacrimal bones These potentially provide dispersal , also them Portugalosuchus Given earliest stratigraphically oldest gavialoids either have nasal gland and/or recovered deposits, this suggests capacity might be ancestral Gavialoidea. Mapping geological onto phylogeny indicates was probably more than one independent loss/reduction

Language: Английский

Citations

5
Aquatic Habits and Niche Partitioning in the Extraordinarily Long-Necked Triassic Reptile Tanystropheus DOI Creative Commons
Stephan N. F. Spiekman, James M. Neenan, Nicholas C. Fraser

et al.

Current Biology, Journal Year: 2020, Volume and Issue: 30(19), P. 3889 - 3895.e2

Published: Aug. 6, 2020

Language: Английский

Citations

33
A new genus of metriorhynchid crocodylomorph from the Lower Cretaceous of Germany DOI
Sven Sachs, Mark T. Young, Jahn J. Hornung

et al.

Journal of Systematic Palaeontology, Journal Year: 2024, Volume and Issue: 22(1)

Published: July 18, 2024

Language: Английский

Citations

4